to some extent, we have gained economically through dirt cheap excess of energy. but it will be costly down the road. we still have time to avert a future where we leave our children and grandchildren a degraded planet, but there's not a whole lot of time. >> basically-judges has been -- basically, our idea has been let's make our children richer and they can figure it out here [laughter] my daughters may live to the end of this century. what are they looking at? >> there is still time to prevent -- most scientists classify it as what would constitute a very dangerous impact on the plan met -- on the planet. we can prevent that. we would have to prevent sued to concentration -- would have to prevent co2 concentration. next year, if we were sitting in this room, rudi 397. -- they would be about 397. you can get to 450 pretty soon if we do not make some dramatic changes. if you do the math -- my good friend has going around the country with the do the math tour. we can still prevent dangerous impacts on our climate. but we have to bring our fossil fuel emissions to